2006 Infiniti G35 Rough Idle - P0300 Random Misfire - Bad Fuel injectors
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- เผยแพร่เมื่อ 29 ก.ค. 2022
- 2006 Infiniti G35 came in with a rough idle. Car had 200,000km so we replaced spark plugs. Still had slight rough idle. Not quite a dead misfire and sometimes worse than others. Seemed to drive pretty well.
These cars don't have misfire counters so not the nicest to track down. Found bank1 fuel trims to be pretty normal. Bank2 were +15% to +25% total trims. Didn't seem to change much with revving the engine. Didn't suspect vacuum leak and nothing found on smoke test. Clear flood crank sounded pretty even.
Checked secondary ignition waveforms with an inductive probe and all looked good. No dropouts seen even though engine was misfiring.
Next easiest step was to check fuel injector current ramp patterns through the fuse. This lead us to the problem. One was very bad, one was partially lower than the "good" ones and one was slightly lower.
Removed the intake manifold and confirmed two bad injectors and one partially bad injector via testing resistance.
After repair the car felt like it had an extra 100 horse power!
I understand the video is a year old now, but is still valuable information. Diagnosing a 2008 Infiniti FX35, has a P0300. (BTW, misfire data on these Nissans/Infinitis is located under the special functions section of your diag. tool. Shows real time and past misfire data.) Misfires are on cylinders 1 and 3, very pronounced fishbite misses. Coils (OEM Hitachi) and plugs (NGK Iridium) are all new and firing, although those 2 cylinders still have what appear as new unused plugs, while the other 4 show obvious signs of combustion events taking place. Ohm readings on the suspect cylinders injectors was 12.2 cold. Using a multimeter on #1 injector and back probing the injector connector, with the key in run, connecting from the Red/Black power and battery neg I'm reading full battery voltage, from the Red ground to battery positive it reads 9.6 volts. Switching to a 300ma incandescent test light, Red/Black probed and grounded to Bat- lights up, but not Red probed and (grounded) to Bat+. With the vehicle running, shows the same low voltage and no injector pulse at all (test light noid light)lol. I can hear both injectors clicking with a stethoscope, not loudly, but audible. Seems like the ground side switch from the PCM is weak or failing. This is also a new to the car PCM from a salvage yard, old PCM apparently was cooking coils on a daily basis. Without a PICO or amp clamp, do you have any suggestions for a next step? Thanks for the content brother!
I think you just solved all my problems bro and now Ik I just needa check the voltage of the fuel injector to test them
So I have a 2006 Infiniti G 35 coupe are you saying that that has clear flood mode? I’d like to do that to eliminate my one second timing chain rattle at cold start up.
dammmmmmmmm. I'm now convinced my p0300 is caused by bad FI. thanxs! I'll do that ohms test as well this weekemd
Can a bad fuel pump cause this I’ve changed out injectors coils and spark fuel rail and cam sensors haven’t touched the crank sensor and ordered new fuel pump it’s a nightmare help me anyway you can please
hey there... what tool is the one you are using at
great video thank you
Hi, I have a 2005 g35 coupe with the rev up motor. I’m about to change out the right VVT Solenoid tomorrow but I’m afraid that’s not gonna be the fix. I’m getting a P0300 and it kinda idles a little rough but never gets too low in the Rpms. It does stutter a little when you try to rev it up or accelerate and get to up to speeds. I think it could be clogged cats, but any help would be greatly appreciated. I haven’t had the chance to get it lifted and get underneath it.
Please where can I place my fuel pressure tester at im so
Cam position sensor bank 1 or 2. Id replace both. Fixed. I just fixed the p0300. A faulty Cam position sensor will give you all types of codes. Replace them thank me later
Mine marked me for service engine soon and I went to go change the ignition coils bc that’s what the scanner marked but it still detects a misfire car smells like gas n runs fine just noticed the loss in power
I have this same problem with a code popping up 03 350z had one for cylinder 1 also but fixed that with new coil packs and plugs now its just P0300 itll idle at 700-800rpm then die down to 500-600rpm and shoot back up car feeels fine driving only happens at idle. Only thing i can think of at this point is bad injectors or an exhaust leak i have and the o2s arent correcting it right. may be wrong but any thoughts please... my obd doesnt read misfires i dont believe
did it fix it ?
Mine has the 0300 code and backfires at idle could it be the same thing
Was the car idling lower than usual?